Automated test equipment (ATE) must test hundreds of thousands of electronic components, ICs or DUTs (device under test) in one test period. The test is always an electronic test. Therefore it is necessary that good contacting for every DUTs is given for the whole test period. Contact tips of contact elements which are integrated in contact sockets make the contact to the terminals of the DUT. During a lot of sequential tests the contact tips may wear down or become soiled so that good contacting of the DUT is no more given. As a consequence, contact tips have been coated with hard material which is more durable against abrasion and which keeps clean for many test cycles. A problem is that the thin hard material coating (usually less than 0.01 mm) tends to wear down or to peel off the contact tip. As a consequence the cost for maintenance and spare parts is high and the positive effects are diminished when using hard material coating.
US 2013/0222005 A1 discloses a contact pin in which a carbon film is formed on a base material, e.g. by a sputtering method, with a tip divided. Sn adherence can be reduced as much as possible to be able to maintain stable electrical contact over a long period of time. The contact probe pin includes a tip divided into two or more projections and repeatedly coming into contact with a test surface at the projection. A carbon film containing a metal element is formed at least on the surface of the projection, and a radius of curvature at an apex part of the projection is 30 μm or more.